1. Field of the Invention
The present invention relates to a portable terminal having a flexible display unit. More particularly, the present invention relates to a display apparatus and method of preventing unnecessary current consumption while improving a battery lifetime of a portable terminal.
2. Description of the Related Art
A portable terminal typically has one or more functions of performing portable audio and video communication, inputting/outputting information, and storing data. As the functions of a portable terminal are diversified, a newer portable terminal, serving as a multimedia player, is equipped with complicated functions, such as capturing of photographs, reproduction of music files or moving image files, games, reception of broadcasts, wireless Internet access, and the like.
More efforts are being made in the hardware or software to implement more complex functions of a portable terminal implemented in the form of a multimedia player. Also, as such a portable terminal is recognized as a personal effect in expressing a user's personality, diverse design choices on both-side LCD and a front surface of the touch screen, and the like, have been demanded. As an example of a user's preference, using the above-described touch screen, the whole area of a portable terminal may be used as a display without a keypad using a touch screen.
Since the portable terminal having the above-described touch screen has a structure in which the area of the display unit cannot be expanded to be wider than the surface area of the portable terminal, there is a need for a technology that can provide a wider screen while minimizing the size of a portable terminal in conjunction with a miniaturization trend.
Recently, a portable terminal having a light thin flexible liquid crystal display unit has been proposed to provide a wider screen, where a liquid crystal display unit is provided on the side surface of the portable terminal to be rolled in during safekeeping and rolled out when in use to provide a display with an aspect ratio that is most familiar to a user. Accordingly, the portable terminal can provide a display which is much wider than the surface of the touch screen, but requires a minimum custody space for accommodating the display unit.
According to the above type portable terminal, however, even in the case where the flexible display unit is rolled or folded by a user, current is constantly supplied to the display portion regardless of the state or mode of the display portion, that is, regardless of whether the display portion is rolled in or expanded out. As a result, as the same current is supplied to the display portion during a rolled in state, unnecessary power is consumed which in turn reduce the battery life time.